docs: def write( structure, name=None ):
      """
      Writes a Structure in PDB format through PDBIO.
      Simplifies life..
      """
      
      from Bio.PDB import PDBIO
      
      io = PDBIO()
      
      io.set_structure(structure)
      
      if not name:
          s_name = structure.id
      else:
          s_name = name
  
      name = "%s.pdb" %s_name
      seed = 0
          
      while 1:
          if os.path.exists(name):
              name = "%s_%s.pdb" %(s_name, seed)
              seed +=1
          else:
              break
                  
      io.save(name)
          
      return name